Buggy code:
public String toString ( ) { } } ; public static final FileFilter SOURCE_FILTER = new FileFilter ( ) { public boolean accept ( File file ) { } public String toString ( ) { } } ; static final int [ ] INT_RA = new int [ 0 ] ; public static final FileFilter ALL = new FileFilter ( ) { public boolean accept ( File f ) { } } ; public static final FileFilter DIRS_AND_WRITABLE_CLASSES = new FileFilter ( ) { public boolean accept ( File file ) { } } ; public static boolean hasZipSuffix ( File file ) { } public static boolean hasZipSuffix ( String path ) { } public static int zipSuffixLength ( File file ) { } public static int zipSuffixLength ( String path ) { } public static boolean hasSourceSuffix ( File file ) { } public static boolean hasSourceSuffix ( String path ) { } public static int sourceSuffixLength ( File file ) { } public static int sourceSuffixLength ( String path ) { } public static boolean canReadDir ( File dir ) { } public static boolean canReadFile ( File file ) { } public static boolean canWriteDir ( File dir ) { } public static boolean canWriteFile ( File file ) { } public static void throwIaxUnlessCanReadFile ( File file , String label ) { } public static void throwIaxUnlessCanReadDir ( File dir , String label ) { } public static void throwIaxUnlessCanWriteFile ( File file , String label ) { } public static void throwIaxUnlessCanWriteDir ( File dir , String label ) { } public static String [ ] getPaths ( File [ ] files ) { } public static String [ ] getPaths ( List files ) { } public static String fileToClassName ( File basedir , File classFile ) { } public static String normalizedPath ( File file , File basedir ) { } public static String flatten ( File [ ] files , String infix ) { } public static String flatten ( String [ ] paths , String infix ) { } public static String normalizedPath ( File file ) { } public static String weakNormalize ( String path ) { } public static String getBestPath ( File file ) { } public static String [ ] getAbsolutePaths ( File [ ] files ) { } public static int deleteContents ( File dir ) { } public static int deleteContents ( File dir , FileFilter filter ) { } public static int deleteContents ( File dir , FileFilter filter , boolean deleteEmptyDirs ) { if ( null == dir ) { throw new IllegalArgumentException ( "null<seq2seq4repair_space>dir" ) ; } if ( ( ! ( dir . exists ( ) ) ) || ( ! ( dir . canWrite ( ) ) ) ) { return 0 ; } if ( ! ( dir . isDirectory ( ) ) ) { dir . delete ( ) ; return 1 ; } String [ ] fromFiles = dir . list ( ) ; int result = 0 ; for ( int i = 0 ; i < ( fromFiles . length ) ; i ++ ) { String string = fromFiles [ i ] ; File file = new File ( dir , string ) ; if ( ( null == filter ) || ( filter . accept ( file ) ) ) { if ( file . isDirectory ( ) ) { result += FileUtil . deleteContents ( file , filter , deleteEmptyDirs ) ; if ( deleteEmptyDirs && ( 0 == ( file . list ( ) . length ) ) ) { file . delete ( ) ; } } else { <START_BUG> file . delete ( ) ; <END_BUG> result ++ ; } } } return result ; } public static int copyDir ( File fromDir , File toDir ) throws IOException { } public static int copyDir ( File fromDir , File toDir , final String fromSuffix , String toSuffix ) throws IOException { } public static int copyDir ( File fromDir , File toDir , final String fromSuffix , final String toSuffix , final List collector ) throws IOException { } public static int copyDir ( File fromDir , File toDir , final String fromSuffix , final String toSuffix , final FileFilter delegate ) throws IOException { } public static String [ ] listFiles ( File srcDir ) { } public static final FileFilter aspectjSourceFileFilter = new FileFilter ( ) { public boolean accept ( File pathname ) { } } ; public static File [ ] listFiles ( File srcDir , FileFilter fileFilter ) { } public static File [ ] getBaseDirFiles ( File basedir , String [ ] paths ) { } public static File [ ] getBaseDirFiles ( File basedir , String [ ] paths , String [ ] suffixes ) { } private static File newFile ( File dir , String path ) { } public static File [ ] copyFiles ( File srcDir , String [ ] relativePaths , File destDir ) throws IOException , IllegalArgumentException { } public static void copyFile ( File fromFile , File toFile ) throws IOException { } public static File ensureParentWritable ( File path ) { } public static void copyValidFiles ( File fromFile , File toFile ) throws IOException { } public static void copyStream ( DataInputStream in , PrintStream out ) throws IOException { } public static void copyStream ( InputStream in , OutputStream out ) throws IOException { } public static void copyStream ( Reader in , Writer out ) throws IOException { } public static File makeNewChildDir ( File parent , String child ) { } public static File getTempDir ( String name ) { } public static URL [ ] getFileURLs ( File [ ] files ) { } public static URL getFileURL ( File file ) { } public static String writeAsString ( File file , String contents ) { }

Fix:
boolean ret = file . delete ( ) ;